This invention relates to animal actuated applicator suitable for applying pesticide or like fluids to animals such as livestock and game. In one embodiment of the invention it relates to an animal actuated applicator adapted for dispensing a volume of pesticide or like fluids in proportion to the animal""s weight.
Numerous applicators for applying active ingredients to animals are known and available in the market. Several of these applicators include a so-called stepping plate or treadle and can be actuated by an animal, for example by a hoof of the animal when the animal treads on the stepping plate or treadle. Known applicators however all suffer from at least one particular disadvantage, namely the inability to dispense variable volumes of pesticide or like treating fluids upon actuation in accordance with the weight of an animal to be treated. Consequently smaller and larger animals often receive equal dosages, potentially resulting in overdosing of smaller animals and/or underdosing of larger animals.
Those who are familiar with the art of dosing animals will appreciate that in order to achieve optimal results from dosing an animal with an active ingredient, such as pesticide or the like treatment fluids, the animal must receive a relatively accurate dosage of the treatment fluid as prescribed by a producer thereof, for example 1 ml treatment fluid per 10 kg body mass of the animal to be dosed. Experience has indicated that many difficulties arise concerning the ease and thoroughness of these types of applications, as well as the duration of their effectiveness. The disadvantages associated with known animal actuated applicators primarily result from the fact that the accuracy of each dosage applied to each animal largely depends on where the annual treads on the stepping plate or treadle.
These disadvantages are more clearly illustrated with reference to the following patent specifications. U.S. Pat. No. 4,165,715 discloses an annual spray apparatus including an inclined ground level treadle supported inside a frame, which defines a stall and which is interposed in the path of an animal, the treadle being biased upwardly by resilient means so that the trade is urged downwardly by the forelegs of an animal stepping thereon, thereby charging dispensing means. The animal is dosed as it exits the stall.
One disadvantage associated with this apparatus is that proper functioning of the apparatus is dependent thereon that the animal is situated all the way in the stall with its forelegs on the treadle and the weight of its hindquarters on the ground. If the animal enters the stall only partly, it will not charge the dispensing means accurately and it will not receive an accurate dosage of active ingredient. Another disadvantage is that, even if proper functioning of the apparatus is achieved, the dispensing means is charged in accordance with only a percentage of the animal""s weight, since its hindquarters is supported on the ground, with this percentage decreasing if the animal is pregnant. Treatment dosages are generally prescribed in a ratio to the total body mass of an animal and consequently this apparatus is not effective in dispensing accurate dosages of treatment fluids. Also, the construction of the apparatus is such that an animal can not pass over the treadle from both directions.
U.S. Pat. No. 3,884,192 discloses an automatic animal sprayer including two platforms arranged in end to end relation, each having their outer ends pivotally connected to a frame and having their inner ends supported by resilient means. The platforms are movable together in a generally vertical direction downwardly in response to the weight of an animal entering onto either platform. Although being an improvement over the previously discussed apparatus, this apparatus also suffers from the disadvantage that the dosing of the animal will depend on where and for what duration of time the animal steps on the platforms. The platforms are required to move downwardly under the weight of the animal so as to overcome the yielding bias of the resilient means and to actuate a pump, as a consequence of which the dosage received by the animal depends on whether the animal adequately crosses over the platforms. Once the pump has been actuated, an animal weighing, for example, 100 kg and one weighing 200 kg will receive the same dosages. Also, the apparatus is relatively complicated in its construction, necessitating enticement of the animals to cross over the platforms and through the frame-structured passage.
The same or similar disadvantages as set out hereinbefore apply to the apparatus disclosed in U.S. Pat. No. 4,126,104.
U.S. Pat. No. 1,460,561 discloses yet a further device for spraying live stock with a treatment fluid. Particularly, this invention provides for a device that comprises a displaceable treadle that is arranged in communication with a dispensing pump and nozzle arrangement. The treadle is located in a doorway of a hog-house, shed or the like with one end of the treadle pivotally connected to a support frame, the floor or the like support base, and the opposite free end of the treadle connected to an upwardly extending rod that has its upper end connected to the dispensing pump. The treadle is maintained in an elevated position by means of a coil spring, the arrangement by such that as an animal treads on the treadle, it depresses the treadle, which in turn effects dispensing of a volume of treatment fluid onto the animal.
A major disadvantage associated with this device is that the dosing of the animal will depend on the exact position where the animal steps on the treadle. So, for example, an animal with weight X who steps on the treadle at a point closer to the treadle pivot point, will receive a similar dosage than an animal with weight xc2xdX who merely steps on the treadle at a point further away from the treadle pivot point and closer to the free end of the treadle.
The device defines a substantially linear relationship between the degree of depression of the treadle and the volume of treatment fluid dispensed. Consequently, smaller and larger animals often receive inaccurate dosages, not only because the treadle has a set stroke, but also because each animal""s dosage depend not so much on the weight of the animal, but on where the animal steps on the treadle. A further associated disadvantage of this device is that repeatability of dosage volumes is impossible. The same animal stepping on the treadle a number of different times each time will receive a different volume of fluid, since the volume dispensed depends on the position where the animal steps on the treadle.
Another disadvantage associated with this type of applicator device is that substantial depression of the treadle is required to effect dispensing of the treatment fluid. However, experience has taught that animals are generally frightened to step onto a surface that gives way under them, as a result of which type of applicator is highly ineffective for use in dosing cattle, game or the like, since the animals simply refuse to walk over the treadle.
It is accordingly one object of the present invention to overcome or at least minimize the aforementioned disadvantages associated with known applicators by providing an animal actuated applicator adapted to dispense variable volumes of pesticide or like fluids in proportion to the weight of the particular actuating the applicator without the necessity of human assistance.
It is another object of the invention to provide an animal actuated applicator wherein dosing fluids can be dispensed in relation to the weight of the particular animal actuating the applicator, regardless of where, in what manner or for how long the animal treads on the actuating means.
It is another object of the invention to provide an animal actuated applicator that permits animals freely and easily to pass over the applicator in either direction without the necessity of force.
According to the invention there is provided an animal actuated applicator suitable for apply in a fluid such as a pesticide to an animal, the applicator comprising
dispensing means for dispensing the fluid; and
actuating means for actuating the dispensing means, wherein the actuating means includes
a base plate which is in use displaced when the animal steps thereon, the degree of displacement being dependent proportionally on the animal""s weight being transferred to the base plate;
at least one pressure lever operatively associated with the base plate and arranged to be displaced in response to the displacement of the base plate; and
an actuator for actuating the dispensing means in response to displacement of the pressure lever to dispense a volume of fluid which is proportional to the animal""s weight being transferred to the base plate.
The actuating means may be suitably dimensioned to be at least partially embedded in an animal pathway. Preferably, the actuating means includes a housing for housing the different components of the actuating means. The housing may be embedded in the ground with the base plate being located at ground level, thereby rendering it the least visible to approaching animals.
The actuating means may include restraining means for restraining the vertical downward displacement of the base plate, the restraining means being located within the housing and centered below the base plate.
The pressure lever may be pivotally connectable at one end thereof to a wall of the housing and may be arranged to abut the restraining means at an opposite end thereof. Preferably, the actuating means includes two pressure levers. More preferably, the actuating means includes four pressure levers, operatively associated with corresponding corner sections of the base plate.
The actuating means may further include first abutting means provided on the base plate, the first abutting means bearing on at least one pressure lever when the base plate is displaced. Preferably, each pressure lever is associated with the base plate by first abuting means. The first abutting means may be studs, buttons or the like formations. Alternatively, the pressure levers may be connected to the base plate by shafts, rods, arms or the like formations.
The dispensing means may comprise a piston-actuated pump, Preferably, the dispensing means includes a calibrated piston and sleeve, volumetric metering arrangement. The dispensing means may be housed removably within a chamber, the chamber being suitably dimensioned to be embedded at least partially in the ground adjacent the housing. The dispensing means may be releasably connectable to any suitable irrigation means for administering the fluid to the animal. The irrigation means may for example be a rose, sprinkler, nozzle or the like. The dispensing means further may be releasably connectable to a reservoir for storing a bulk volume of the treatment fluid.
According to one embodiment of the invention the restraining means may be a float, the float being operatively associated with the base plate by means of the pressure levers and arranged to be displaceable vertically in a liquid carrier within the housing in proportion to the animal""s weight being transferred to the base plate. In this embodiment the dispensing means may be operatively associated with the float by means of an actuator arm extending from the float, the dispensing means being capable of dispensing a variable volume of fluid in accordance with the vertical displacement of the float.
The float may consist of a low-density body. Preferably the float consists of a low-density panel for floating on the liquid carrier such as water.
In an alternative embodiment of the invention, the resting means may be a spring, for example a coil spring or a laminated spring, operatively associated with the base plate and arranged to be compressed upon displacement of the base plate. The dispensing means may he operatively associated with the actuating means through an actuator arm extending from the pivotally connected end of at least one pressure lever.
Alternatively the restraining means may be magnets, such as permanent magnets or electromagnets, operatively associated with the base plate and arranged to create a repulsive force between them when the animal steps on the base plate so that the repulsive force may be increased in proportion to the animal""s weight.
According to yet another embodiment of the invention the actuator may be an electronic arrangement including electronic sensing means, such as a load cell or the like, the electronic sensing means being operatively associated with the base plate by means of the pressure levers and being capable of sensing at least a portion of the animal""s weight. In this embodiment, the electronic sensing means may be connected to a microprocessor control unit arranged in communication with the electronic sensing means and adapted to activate the dispensing means to dispense a variable volume of fluid in proportion to the weight of an animal as sensed by the electronic sensing means.
It will be appreciated that the sensitivity of the actuating means to the relative weight of different animals may have a finite range bordered by a predetermined minimum and maximum limit. If in use the animal""s weight is below the minimum limit the applicator will not be actuated. If, on the other hand, the animal""s weight is above the maximum limit, the dispensing means will dispense a maximum volume of fluid and will not dispense a volume of fluid proportional to the animal""s weight.